Agree with SPB
The backdrop of this is that women in US generally have to pay for contraception. Thus women who are addicts are unlikely to spend their money on contraception when they could spend it on drugs. Ditto if a drug addict in US wanted a coil fitted or to be sterilised she would have to pay.
Then there is the US attitude to abortion, the idea that drug addicts may become pregnant and then access abortions is (as you can imagine) a huge huge deal in US. (Obviously it is terrible everywhere, but the pro-life lobby in US is a lot more vocal and extreme than here).
So when you put all of those things together, then maybe offering money for long term contraception in US makes sense. Not sterilisation, obviously. The point being that in the US, the women can;t make that choice as it'll cost them. (There are some free clinics I think, but it's a general principle).
In teh UK, contraception is frely available and heavilty promoted, Women who are drug addicts will be offered long term contraceptive solutions by their GP, outreach workers, all sorts of agencies. If they have not taken it up, maybe there is a reason why. Bribing them to do it seems wrong. And the way the payments are fixed - you get a big lump sum for sterilisation, smaller paynents over a period of time for otehr methods - well if you want the cash for drugs you're going to go for option A.
The whole thing is totally immoral. Before we even get into the fact that this affects women more than men, that it is people in poverty who are being targetted etc etc.